今天在搭备库的时候报了下面的错误：
RMAN> duplicate target database for standby from active database nofilenamecheck;
Starting Duplicate Db at 2018/05/17 16:32:14
using target database control file instead of recovery catalog
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of Duplicate Db command at 05/17/2018 16:32:15
RMAN-05501: aborting duplication of target database
RMAN-03009: failure of allocate command on ORA_AUX_SBT_TAPE_1 channel at 05/17/2018 16:32:15
ORA-19554: error allocating device, device type: SBT_TAPE, device name:
ORA-27211: Failed to load Media Management Library
Additional information: 2分析后发现，源端的device type 为 DISK ，目的端device type TAPE，所以导致的了该错误